Elastic link straps



March 15, 1960' L. KUNZMANN 2,928,232

ELASTIC LINK STRAPS Filed Oct. so, 1956 I 2 Sheets-Sheet 1 IN V EN TOR.L U l/YWIG- KUNl MANN MMJIOL! 5. y,

March 15, 1960 L. KUNZMANN 2,928,232

7 ELASTIC LINK STRAPS Filed Oct. 30, 1956 2 Sheets-Sheet 2 INVENTOR.LUDWIG KUNZ MANN BY mlmi sv sum ELASTIC LINK STRAPS Ludwig Kunzmann,Pforzheim, Germany, assignor to Rodi & Wienenberger Aktiengesellschaft,Piorzheim, Germany Application October 30, 1956, Serial No. 619,193

Claims priority, application Germany October 4, 1956 3 Claims. (Cl.59-79) The present invention relates to new improvements in elastic linkstraps for ornamental or utilitarian purposes, and especially in watchbracelets. More particularly, the invention relates to that type ofelastic link straps which consists of two superimposed layers of linkswhich in the contracted position of the strap are staggered relative toeach other by the width of one-half link as seen in the longitudinaldirection of the strap, and in which the individual upper and lowerlinks form hollow casings, the respective lower and upper sides of whichfacing toward each other are open, while the transverse side walls ofthe adjacent links of one layer engage into the links of the otherlayer, and'wherein curved leaf springs are mounted between these sidewalls which are pressed flat when the strap is being expanded. I

It is an object of the present invention to provide certain new anduseful improvements in an elastic link strap of the general type asdescribed above in which the upper.

and lower links are connected with each other so as to be movablerelative to each other in the longitudinal direction of the strap.

' A feature of the invention for attaining this object consists inproviding the transverse side walls of the links of one layer with slotswhich extend inwardly from a point at or near the outer edges of thelinks, and in providing each of the links of the other layer withextensions at-the opposite ends thereof which are then bent so as toform a pair of transversely extending tabs or crossbars which projectinto the slots in the links of the other layer and thus serve both asconnecting members for securing the upper and lower links to each other,and as guiding members along which the slotted links of the other layermay slide in the longitudinal direction of the strap relative to thelinks carrying these transverse tabs or crossbars.

In several preferred embodiments of the invention, this feature consistsin providing the outer ends 'of the lower links with slots extendingtoward eachother, and in bending a pair of outer extensions of the upperornamental wall of the upper links downwardly and them toward each otherand into the slots in the ends of the lower links so as to be slidabletherein in the longitudinal direction of the strap.

'It is another important object of the invention to provide an elastictwo-layer link strap of the smallest possi ble thickness.

According to one embodiment of the invention this object is attained bymaking the lower links in the form of a substantially flat bottom platewith a pair of side walls thereon extending at substantially rightangles thereto and transversely to the longitudinal direction of thestrap. These side walls of the lower links are provided at their outerends with projecting tongues which preferably are rounded offseinicircularly at their outer ends, while the extensions of the upperwall of the upper links are bent downwardly over these semicirculartongues. and inwardly toward eachother andinto the, outerslots nitedStates Patent t ice portions. The height of the side walls of the lowerlinks which are designed to extend into the upper links through thelower opening thereof, and the height or width of the tongues on theseside walls may be made of any desired size and in accordance with thedimensions of the upper links so as to make the combined thickness ofthe upper and lower links as small as possible. For this purpose, theslots in the ends of the side walls of the lower links are preferablydisposed so as to be immediately above the bottom plate thereof so thatthe latter forms the lower edges defining the slots.

According to another embodiment of the invention, the thickness of thestrap may be further reduced so that the lower links will not add at allto the thickness of the upper links and the entire thickness of thetwo-layer strap will'be merely that of the upper links. For thispurpose, the slots in the side walls of the lower links are providied atsuch a low point so that they will re main only. in the form of notchesorrecesses in thelower outer ends of'the, side walls, each being limitedonly by its inner edge and the lower edge of the projecting tongue overwhich the respective extension of the upper ornamental wall of the upperlink is bent. The bottom plate of each lower link is then shortened atboth ends to the inner end of the notch or recess, and such notches arethen only made of a width in the vertical direction so as to correspondsubstantially to the thickness of the material of the extensions of theupper link walls which are bent toward each other into such notches.

Another object of the present invention is to simplify the design andconstruction of the various elements of a two-layer link strap, and toreduce the cost of production of such a strap. According to oneembodiment of the invention this object as well' as the object pre eachother and the thickness of the strap will be no more than the thicknessof the upper links plus the thickness of the material of the bottomplate of the lower links.

Both the upper and lower links are then similar to the lower linksof'one of the first-described embodiments of the invention and eachconsist of a substantially flat outer plate with side walls thereonextending at right angles thereto and provided with slots at the outerends thereof which are formed by the space between the tonguesprojecting outwardly from the lower ends of-the side walls of the upperlinks and the upper ends of the.

side walls of. the lower links, respectively and the extensions of therespective outer walls of the upper and lower links, that is, theornamental upper wall of the upper linksand the bottom plate of thelower links, which are bent toward the links of the other layer and thenin, wardly toward each other. These bent-over extensions then formpockets at both ends of each link in which the tongues of the links ofthe other layer are guided for movement in the longitudinal direction ofthe strap when the upper and lower links are inserted into each other.

.According to still another embodiment of the invention, the slots areprovided in the side walls of the links of one layer and, in theassembled structure, the respective outer walls of such links, that is,the ornamental aeeaasa.

ward direction. Since the outer ends of the slots are thus closed, it isno longer possible to insert the extensions of the outer wall of thelinks of the other layer into them from the outside to connect the upperand lower links to each other, but it is then necessary to pro-. vide acrossbar at each end of the links opposite to those in which thementioned slots are provided, andfto insert such crossbars into theslots. These crossb'ars are likewise formed by extensions of the wallsof the latter links, but in this case they are not providedon the outerwall as in the previously described embodiments but on the side walls ofthese links and at a level depending upon the level of the slots orapertures in the side walls of the opposite links. These extensions are.made of a thickness substantially corresponding to thewidth of theslots in the other links, as seen in the vertical direction, whilethelength of the slots is then also made so as to correspondsubstantially to the thickness of the material of the links and theextensions thereon. The extensions at thecorresponding ends of both sidewalls ofthese links.

are then bent toward each other so as .to form a cross bar which isinserted into the slots in the side Walls of toward the other iayer soas to cover. the .crossbars and.

close the partly open ends of these links. The free ends oi'thebent-over extensions of the links of both layers then face each otherand slide closely along each. other when the strap is being expanded orcontracted. thickness of the strap according to this embodiment of theinvention is therefore likewise equal to the thickness of the link ofonly one layer plus the thickness of the material of one outer linkwall. A further object of the present invention is to provide atwo-lryerelastic link strap of the type as previously described, theindividual links or which may be easily separated from each otherwithout unbending any parts thereof to permit the strap to be lengthenedor shortened by the insertion of additional links or the removal of oneor more links' Another objectofthe invention is to provide such a.

strap with means which will only permit theindividual links to beseparated intentionally and, will prevent the strap from ever comingapart accidentally.

This object may be attained in the embodiments of the invention as firstdescribed by providingat least someof the upper linkswith a recess orcutout at-or near one.

outer corner of the free edge of one of the two bentver extensionsadjacent to one side wall of-suchlinks, andi'by shorteningthe respectivetongue on the side wall-of one of the two lower links which is beingoverlapped by suchv extension to such an extent that such shortenedtongue may be slipped through such cutout and'thc respective lower linkmay be unhooked from the upper link. order to prevent the links frombecoming unintentionally unhook'ed from each other, it is merelynecessary to shorten one tongue of that of two adjacent lowerlinksentering into one upper link which moves away: from the cutout at oneside of the free edge of the bent-over extension of the upper link whenthe strap is being expanded.

Another feature of the invention for shortening or lengthening theelastic strap according to the first de scribed embodiments consists inshortening the tongues at both ends of one side wall of at least someofthe lower links to such an extent that such side wall may be 70with.recesses at its lower side so assubstantiallytocore-- The.

respond in shape to the notches or slots in the uncut side wall of thelower link. The bent-over extensions of the upper link engage into theselower recesses in the connecting member and thus retain the same in theupper link, but so as to be slideable in the longitudinal direction ofthe strap. The bottom wall of the respective lower link is then providedwith a .hole in which a screw is mounted which'is'screwed into'athreaded hole in the connecting memberto secure the latter removably tosuch lower link. Particularly if the. individual. links of the strap areto be made very narrow, each of theconnecting members may be providedwith a central reinforcing portion for receiving the screw hole, whileone side wall of the upper link may then be provided with acorresponding cutout for receiving such reinforcing portionj However,the connecting member may also be made of angular shape, one arm ofwhich is provided to abut against one side wall of the upper link, whilethe other arm abuts against the bottom wall of the lower link tov whichit may be removably secured.

In all of the embodiments of the invention as previously described, itis advisable to make the lower links of smaller width than the upperlinks so that gaps will remain between. the adjacent lower links evenwhen the strap is in itscompletely contracted position and the skinandhairs on the hand and wrist of the wearer cannot be caught between theselinks.

7 Further objects, features, and advantages of the present; inventionwill appear from the following detailed descrip tion. thereof,particularly when read with reference to the accompanying drawings, I inwhich:

Fig. 1 shows, partly in crosssection, a side viewof a portion of a linkstrap illustrating the principle of the present invention;

Fig. 2 shows a cross section taken along line lI-II of. Fig. 1;

i Fig, 3 shows a perspective view of an upper, linkaccording to a firstembodiment of theinvention;

Fig. 4:shows a perspective view of the corresponding lower link;

:Fig. 5 shows a perspective view of a leaf spring;

Fig. 6 shows a fractional cross section of-an upper and lower linkaccording to Figs. 3 and 4 in their engaged position with each other, asseen'in-a direction transverse tothe longitudinal d rection of thestrap;

Fig; 7 showsa view similar to'Fig. 6 ofa modification. ofthe lower link;

Fig. 8 shows a perspective view of an upper link according to Fig. 3,but'in the inverted position;

Fig, 9 shows a horizontal cross section through two linksin theprocessof being disengaged'from each other when the strap is to be shortened;

Fig. 10 shows a vertical longitudinal cross section through .two links.ofv both layers according to-anotherembodiment of the invention;

Fig. 11 shows a. perspective .view of a lower link ac cording to Fig.10;

Fig. lZshows a perspective view of a connecting meme ber accordingtoFig. 10;

Fig. 13 shows a perspective view of a modified connecting member;

Fig. 14 shows a perspective =view of an upper link to be used incombination with a connecting member according. to Fig. 13; V

Fig. 15 shows a perspective viewof an upper linkaccording to anothermodificationof the invention;

Fig. 16 shows a perspective viewof the corresponding lower link;

Fig. 17 shows a perspective view of an upper link or. still anothermodification of the invention; while.

Fig. 18' shows a perspective view of the corresponding lower link.

Referring to the drawings; and'fi'rst particularly to Figs. land 32which are=merelyintended to illustrate the basic principlessofi' thepresent invention; the new elastic linkstrap consists generally of aplurality of upper linksY10 which form hollow casings which are open inthe downward direction, and each of which has an upper wall 11, sidewalls 12, end walls 13 which form downwardly bent extensions of theupper wall L1, and inwardly bent tabs or bars 15 which form extensionseither of the end walls 13, as shown in Figs. 1 and 2, or of side walls12. The lower links 30 are open in the upward direction and each have abottom wall, transverse side walls 31, and end walls 33, which end wallsmay, however, be omitted according to some embodiments of the invention,their function then being taken over by the end walls of the upperlinks. One side wall 31 of each of two adjacent lower links 30 projectsinto one upper link 10, and these side walls 31 are provided at or nearthe outer ends with slots or recesses 32. Extensions 15 of the upperlinks 10 are bent inwardly so as to engage into these slots 32 toconnect the upper and lower links 10 and 3t? with each other so as to beslideable relative to each other in the longitudinal direction of thestrap. The upper links 10' further contain leaf springs 50, and thesesprings are inserted between at least one of the side walls 12-of eachupper link and one side wall 31 of at least one of the two associatedlower links 30, and are pressed flat between these side walls when thestrap is being expanded, thus tending to contract the strap.

The strap as illustrated in Figs. 1 and 2, although thinner thanprevious two-layer straps, is still relatively thick. Also, due to thetroughlike :shape of the lower links 30, dirt may easily collecttherein. This will be avoided in the embodiments of the invention, asshown in Figs. 3 to 14. The lower links 340i the embodiment:

shown in Fig. 4 are therefore devoid of any end walls and only consistof a substantially flat bottom plate 35 with two side walls 36 extendingupwardly therefrom at a right angle thereto and provided at each endwith a tongue 37 extending beyond bottom plate 35 and preferably roundedofi semi-circularly. Between tongues 37 and the upper edges of bottomplate 35 and directly adjacent thereto, side walls 36 are provided withinwardly extending slots or recesses 38. The corresponding upper link15, as shown in Fig. 3, consists of an upper plate 16 which forms a partof the ornamental surface of the strap, side walls 17 extendingtransversely to the longitudinal direction of the strap, and outerextensions on upper plate 16 which are bent over downwardly and theninwardly so as to form semicircular end walls terminating in oppositetabs 13. The ends of side walls 17 are provided with notches 19. Whenthe individual parts of the strap are being'assembled and extensions 18are then bent downwardly and inwardly and into notches 19, as shown inFigs-3 and 6, they will curve around tongues 37 of lower links 30 andthe lower surfaces of their inwardly bent ends will then be disposed atan even level with the edges of side walls 17 defining the bottomopening of each upper link and extend into slots 38 in side walls 36 ofthe lower links so as to be slideable therein in the longitudinaldirection of the strap. During such assembly, a pair of curved leafsprings 50 is also inserted into each upper link 15 so that each springwill then be mounted between one side wall 17 of an upper link 15 andthe corre-' sponding side wall 36 of one of the two lower links 34 whichare associated with such upper link, as shown in Figs. 1 and 9. Eachspring 50 is undercut at its lower side near its outer rounded ends soas to form bearing surfaces 51 on which springs 50 may rest on therounded inner end surfaces of extensions 18 of upper links 15.

Fig. 7 shows a modification of the lower links 34. Bottom plate 35 isshortened at each end, as compared with the embodiment shown in Figs. 4and 6, and. side walls 37 are notched out accordingly by substantiallythe thickness of the material of tabs 18 of upper links 15. Thisembodiment therefore does not require any special slots in side walls37' thereof, and the assembled upper and lower links will be stillthinner than those shown in lowersurface of bottom plate 35 of the lowerlinks.

While the elastic strap as previously described does not permit anyremoval of any links or insertion of addi-v tional links in order toadjust the strap to a smaller or thicker wrist, unless one or more upperlinks are unbent and then rebent to disconnect them from the lowerlinks, as well as from each other, and to reconnect them thereto, Figs.4, 8 and 9 also illustrate a modification of the invention which permitssuch removal or insertion of one or more links to be carried out withoutany tools and Without bending orunbending any links which might leavepermanent marks on the strap and harm the appearance thereof.

Fig. 8 illustrates one of the upper links as shown in Fig. 3 in theinverted position. While in the previously described embodiment it wasassumed that tabs 18 forming the bent-over ends of theex-tensions ofupper plate 16 of the upper links extended fully from one side wall 1'7thereof to the other, Fig. 8 shows one end of one of the two tabs 18 asbeing provided with a recess or cutout 20. If this cutout 20 should behidden from the outside, it may be made of U-shape so that a narrowouter tongue will close the respective notch 19 in the adjacent sidewall 17, or such notch may be made of shorter length. If thecorresponding tongue 37 on one side wall 36 of one of the two lowerlinks 34 which are associated with the between side Walls 36 of lowerlinks 34 and side walls 17 of the upper links, and then, while holdingthe adjacent links in such expanded position, to turn one of the lowerlinks 34 which has such a shortened tongue 37" to an oblique positionopposite to the direction of exp-ansion of the strap, as illustrated inFig. 9, so that the end of the side wall of such lower link whichcarries the shortened tongue 37" will be pushed back and placed in linewith the cutout 20. The shortened tongue 37 may then be slipped throughcutout 20, and the other full tongue 37 on such side wall 36 may thenalso be unhooked from the opposite tab 18 of the upper link 15. In thesame manner it is also possible again to hook the lower link 34 into therespective upper link 15. In order to prevent the links from becomingunhooked unintentionally, it is advisable to provide the shortenedtongue 37" on the side wall 36 of that of the two lower links engaginginto the respective upper link 15 which is moved away from, rather thantoward, cutout 20 in the upper link. This cutout 20 should, however,only be made of H a depth so as still to leave a sufficiently largesupporting surface betweenits edge and the outer end of the full oruncut tongue 37 of the side wall of the adjacent lower link so that thistongue can under no circumstancesslip out through this cutout 20. Figs.10 to 14 illustrate another possibility according to the invention ofshortening the new strap. The lower link 40 in Fig. 11 corresponds inshape generally to lower link 34 as shown each upper link 15 contains anangular connecting member 45, as shown in Figs. 10 and 12, the higherside of which engages with the inner surface of one side wall 17 whenthe strap is in the released position, and the outer ends of which areprovided at'the lower side thereof a sc ssa 7. with recesses'fi intowhichztabs 18 of the-upperlinklS' project so as to secure connectingmember l-v thereto.

Connecting. member 45 is then removably secured fro/the,

bottom plate 41' of'the'lower link 40 by a' screw 47. Thus; after screw47 hasbeen removed, theshorter side wall 43 may thenbe removed from theupper. link without requiring tabs 18 to beunbent.

If the links of the. strap are made very narrow, it may be advisable ornecessary to reinforce or enlarge the central part of connecting member48 so as to provide sufficient material for the wall of the bore forscrew 47. In such a case, connecting member ifinmay be madeof a shape asshown in Fig. 13, in which the central partthereof has a reinforcingprojection 49, while the upper link 15, as shown in Fig. 14, is providedwith acentral cutout 21 in its one side wall 17 whichis adapted toreceive the projection 49.

Since it is hardly ever necessary that more than a few links be removedto shorten the strap sufiiciently to. comply with the circumference ofthe wrist of any wearer thereof, only a few links need be made removablein either of the ways as described above. For easier identification,such removable links may then preferably be marked in a suitable manner,for example, on the lower:

surface of the lower links.

Figs. lSand 16 illustrate amodification of the upper and lower linksaccording to the invention andof the means of connecting and guiding thesame relative to each other. The upper and lower links 6!) and 70,respectively, are of exactly the same shape and consist of asubstantially flat plate 61 or 71 which forms eithertheouter ornamentalsurface of the upper link dtli-or the lower arm-engaging surface of thelower link 70, res-. pectively, and carries a pair of side walls'62 or72, respectively, in which horizontal slots 63 or 73 are .pro-.

vided at the outer ends'thereof which thus form outer tongues 64 or 74,respectively. The outer end portions of the fiat plates 61 and 71 arebent over downwardly or upwardly, respectively, and their free'endsproject.

into slots 63 and 73, respectively, of the same links so as'to formpockets on and 76, respectively, in which tongues id-and 64 of therespective link of the other.

walls 62 and 72 while theends 65 and 75 are still unbent.

75 of the lower links 7tlare bent over and around tongues Thereafter,ends 65 of upper links 60 and ends 74 of the lower links and tonguesv 6dof the upper links, and into slots 63 and 73 in side walls 62 and'72,respectiveiy, so that tongues'74 of lower links 74 are enclosed by theends 65 of the upper links 60 and tongues 64' of the upper links'fiil bythe. ends 75' of the lower links 70. Also in this embodiment of theinventionit is preferred to round off the tongues 64 and 7esemicircularly so that the overlapping ends 65 and 75 will be of asimilar semicylindri cal shape.

While in each of the embodiments of the invention as previouslydescribedithe upper and lower links are connected to and guided alongeach other by the bentover tabs or ends of the outer walls of the linksof one or both layers, the arrangement is made slightly differentinthe'embodiment shown in Figs.- 17 and 18', insofanas herein the lowerlinks t} are. provided with cross arms E34 which, when the strap isassembled, engage inslots 83. inxtheside walls .82 of upper links fill.Each of the uppeL-linksSil againxconsists of an upper ornamental plate;81;witli.side walls 32 thereon. and at right, angles thereto, andbent-over ends 85 of plate: 81 whichv tolinks 90. consistof a bottomplate- 91 with side walls 92atright angles thereto, and a-pair or" crossarms 94- onieachside wall 92 which are also, bent at right angles andtoward those of ,the other side wall 92. The bentover ends of the upperlinks 8% of this embodiment only serve to cover the end openings of thelower links 90. These links may, however, also be provided with endwalls 95 which form extensions of the bottom plate 91 and are bentupwardly either so as to be in sliding engagement with the lower edgesof the ends 35 of'the upper links or to overlap these endsor to beoverlapped thereby. Of course, the arrangement may also be reversed sothat the cross arms 94 may be provided on the upper links 32 and slots33 in the lower links 92. Similarly, the strap according to the otherembodiments of the invention may be reversed, so that the upper links asshown in the drawings serve as lower links and the lower links as upperlinks.

in all of the embodiments of the invention, it is advisable to make thewidth of the lower links smaller than that of the upper links so thatgaps will be formed between the adjacent lower links when the strap isin the fully contracted position when the adjacent upper links engageeach other,- whereby the skin or hairs on the hand and wrist of thewearer-will not be caught be tween the edges of the lower links.

'Although the invention has been illustrated and described withreference to the preferred embodiments thereof, it is to be understoodthat it is in no way limited tions, at least one of said channel-shapedend po1tions having in the free edge thereof a cut-out adjacent one ofsaid first side walls located at one corner of said rectangular opening;a set of second links alternately arranged with said first links, eachsecond link having a main wall and two transverse second side walls andbeing arranged with said second side walls respectively located in twoadjacent first links and passing through the respective openings, one ofsaid second side walls having at each end thereof a longer extension andthe other of saidsecond side walls of each second link having-only.

at one end thereof a longer extension andat the other end thereof ashorter extension, said extensions projectlog into said channel-shapedendportions of the respec-- tive associated first link, one of saidlonger, extensions of said one second side wallslidably engaging saidcutout edge also in the region of said cut-out, and saidshorterextension of said other second sidewall slidably engaging said cutoutedge only outsideof said cut-out,- said other second side walls beinglonger than the transverse distance between said free edges of saidchannelshaped end portions, and the length ofsaid other second side wallfrom the inner end of its longer extension to the outer free end of saidshorter extension being shorter than the distance between thedeepestpoint of said cutout in said-one corner and. the diagonallyopposite cornerof said rectangular opening so that said shorter exttensionpasses through said cut-out only when the respectiveother secondside wall is placed in contracted position of said link strap in thediagonal of said'rectangular opening" whereby said second links can bethreaded through said cut-outs for removal, said one second. side, wallof each second link being normally located opposite said one of saidfirst sidewalls of the associated first link; and a set of resilientmeans, each resilientmeans being located between a first side wall and asecond side wall to urge said link chain into a contracted position. Y

2. An elastic link strap comprising, in combination, a set of firstlinks, each first, link having a main wall including two inwardlyopening channel-shaped end portions extending in longitudinal directionof the link strap and a pair of transverse first side walls so that eachfirst link has a rectangular opening between said first side walls andthe free edges of said channel-shaped end portions, at least one of saidchannel-shaped end portions having in the free edge thereof a cut-outadjacent one of said first side Walls located at one corner of saidrectangular opening; a set of second links alternately arranged withsaid first links, each second link having a main wall and two transversesecond side walls and being arranged with said second side wallsrespectively located in two adjacent first links and passing through therespective openings, the longitudinal edges of said main walls of saidsecond links being located opposite the free edges of saidchannel-shaped end portions of the associated first links so as to forma flush surface, one of said second side walls having at each endthereof a longer extension and the other of said second side walls ofeach second link having only at one end thereof a longer extension andat the other end thereof a shorter extension,

said extensions projecting into said channel-shaped end portions of therespective associated first link, one of said longer extensions of saidone second side wall slidably engaging said cutout edge also in theregion of said cut-out. and said shorter extension of said other secondside wall slidably engaging said cutout edge only outside of saidcut-out, said other second side walls being longer than the transversedistance between said free edges of said channel-shaped end portions,and the length of said other second side wall from the inner end of itslonger extension to the outer free end of said shorter extension beingshorter than thedistance between the deepest point of said cut-out insaid one corner and the diagonally opposite corner of said rectangularopening so that said shorter extension passes through said cut-out onlywhen the respective other second side wall is placed in contractedposition of said link strap in the diagonal of said rectangular openingwhereby said second links can be threaded through said cut-outs forremoval, said one second side wall of each second link being locatedopposite said one of said first side walls of the asscoiated first link;and a set of resilient means, each resilient means being located betweena first side wall and a second side wall to urge said link chain into acontracted position.

3. An elastic link strap comprising, in combination, a set of firstlinks, each first link having a main wall including two inwardly openingchannel-shaped end portions extending in longitudinal direction of thelink strap and a pair of transverse first side walls so that each firstlink has a rectangular opening between said first side 10 walls and thefree edges of said channel-shaped end portions, at least one of saidchannel-shaped end portions having in the free edgethereof a cut-outadjacent one of said first side walls located at one corner of saidrectangular opening; a set of second links alternately arranged withsaid first links, each second link having a main wall and two transversesecond side walls and being arranged with said second side wallsrespectively located in two adjacent first links and passing through therespective openings, one of said second side walls having at each endthereof a longer extension and the other of said second side walls ofeach second link having only at one end thereof a longer extension andat the other end thereof a shorter extension, said extensions projectinginto said channel-shaped end portions of the respective associated firstlink, one of said longer extensions of said one second side wallslidably engaging said cutout edge also in the region of said cut-out,and said shorter extension of said other second side wall slidablyengaging said cutout edge only outside of ,said cut-out, said othersecond side walls being longer than the transverse distance between saidfree edges of said channel-shaped end portions, and the length of saidother second side wall from the inner end of itslonger extension to theouter free end of said shorterextension being shorter than the distancebetween the deepest point of said cut-out in said'one corner and thediagonally opposite corner of said rectangular opening so that saidshorter extension passes through said cut-out only when the respectiveother second side Wallis placed in contracted position of said linkstrap in the diagonal of said rectangular opening whereby said secondlinks can be threaded through said cut-outs for removal, said one secondside wall of each second link being located opposite said one of saidfirst side walls of the associated first link; and a set of curved leafsprings, each leaf spring being located between a first side wall and asecond side wall to urge said link chain into a contracted position,each leaf spring having end portions projecting into said channel-shapedend portions, each end portion of said leaf springs having a recessmatching the respective free edge of said channel-shaped portion andbeing spaced from the same to permit moving apart of said end portionswhensaid curved leaf spring is compressed.

References Cited in the file of this patent UNITED STATES PATENTS1,184,534 Jolly May 23, 1916 1,677,204 Person July 17, 1928 1,700,293Lederer Ian. 29, 1929 FOREIGN PATENTS 7 10,916 Great Britain of 1910213,632 Great Britain Apr. 1, 1924 OTHER REFERENCES Pfisterer: Germanprinted application No. 12571 III 44a, printed March 22, 1956.

